The present invention relates to an apparatus and method for capturing a wire in a blood vessel, and is particularly directed to an apparatus and method for capturing a guide wire used in connection with an endovascular prosthesis.
Vascular aneurysms, which result from abnormal dilation of a blood vessel, can occur in any blood vessel. For instance, vascular aneurysms can occur in the aorta and peripheral arteries. The majority of aortic aneurysms occur in the abdominal aorta below the renal arteries. Often the abdominal aortic aneurysm extends into areas of bifurcation (e.g., the inferior end of the aorta where it bifurcates into the iliac arteries) or segments of the aorta from which other branch arteries extend.
Techniques have been developed for repairing abdominal aortic aneurysms by intraluminally delivering an endovascular graft to the aneurysm site through the use of a catheter-based delivery system. The endovascular grafts typically comprise a tube of pliable material (e.g., expanded polytetrafluoroethylene (ePTFE) or woven polyester) in combination with a graft anchoring component, which operates to hold the tubular graft in its intended position within the aorta. Most commonly, the graft anchoring component is formed of a stent or frame that is radially expandable to exert outwardly directing radial pressure against the surrounding blood vessel wall. The stent or frame can be either attached to or incorporated into the body of the tubular graft or provided separate from the graft and deployed within the graft.
Unfortunately, not all patients diagnosed with abdominal aortic aneurysms are considered to be candidates for endovascular grafting. Most endovascular grafts, which have been designed for treating abdominal aortic aneurysms, require the patient being treated have a proximal aortic neck inferior the renal arteries of at least 1 cm in length and a distal iliac neck less than 2.0 cm in diameter.
Additionally, the deployment of endovascular grafts within regions of the aorta from which the renal, superior mesenteric, celiac, intercostal, and/or subclavian arteries extend present additional technical challenges because, in those cases, it is advantageous to design, implant, and maintain, the endovascular graft in a manner which does not impair the flow of blood into these arteries.
The present invention is an apparatus for capturing a wire within a lumen of a blood vessel. The apparatus comprises a tube having a proximal end and a distal end. The distal end of the tube is adapted for placement within the lumen of a blood vessel. A wire loop extends from the distal end of the tube. The wire loop has a substantially cardioidal shape. The apparatus further includes a means for constricting the wire loop.
The present invention also provides a method of intraluminally transferring a guide wire from a first branch artery of the aorta to a second branch artery of the aorta. In the method, a guide wire with a proximal end and a distal end is positioned in a first branch artery of the aorta. The distal end of the guide wire extends from the first branch artery into the aorta and the proximal end of the guide wire extends through the first branch artery.
A snare instrument is advanced through a second branch artery of the aorta to the aorta. The snare instrument includes a tube and a snare wire. The tube has a proximal end and a distal end. The snare wire extends within the tube and is capable of being extended from the distal end of the tube to form a wire loop having a first curved portion, a second curved portion and a cusp portion.
The snare wire is advanced from the distal end of the tube within said aorta so that said snare wire forms the wire loop with the first curved portion, the second curved portion, and the cusp portion.
The proximal end of the guide wire is inserted through the wire loop. The wire loop is constricted to capture the proximal end of the guide wire. The surgical instrument is withdrawn with the captured proximal end of the guide wire through the second branch artery.